The Second Commonwealth in England refers to the period of English history that followed the execution of King Charles I in 1649 and lasted until the restoration of the monarchy in 1660. During this time, England was ruled as a republic, with executive power held by the Council of State and legislative power held by the Rump Parliament.

The Commonwealth was established by the Puritan leader Oliver Cromwell, who served as Lord Protector of England from 1653 until his death in 1658. Cromwell was a military commander who had played a key role in the English Civil War, which was fought between the forces of Parliament and those of King Charles I.

Under Cromwell's leadership, England underwent significant changes. The country was governed according to Puritan principles, with strict laws enforced against activities such as drinking, gambling, and theatre. The Commonwealth also saw the establishment of a professional army and navy, which were used to extend English influence overseas. England became a republic, with the head of state being the Lord Protector rather than a monarch.

Under Oliver Cromwell's rule, England was governed by a structure of government that was based on a written constitution known as the Instrument of Government. This constitution established the position of Lord Protector, which Cromwell himself held, as the head of state and gave him significant executive powers. The constitution also provided for a Parliament, which was made up of a House of Commons and a House of Lords, although the latter was not actually established during Cromwell's rule.

Cromwell's government was characterized by a strong centralization of power and a focus on efficiency and effectiveness. He created a professional army and navy that were used to extend English influence overseas and protect the country from external threats. Cromwell's foreign policy was aggressive and expansionist, and he fought several wars during his time in power.

One of the most significant conflicts was the Anglo-Dutch War, which lasted from 1652 to 1654. This war was fought between England and the Dutch Republic over trade and economic interests in the North Sea and the Atlantic. The English ultimately emerged victorious, securing their dominance in trade and shipping.

Cromwell also fought a series of wars against Scotland and Ireland, which were seen as threats to the stability of the new regime. In Scotland, Cromwell's army defeated the forces of the Scottish Covenanters in a series of battles, culminating in the Battle of Dunbar in 1650. In Ireland, Cromwell led a brutal campaign against the Irish Confederates, which included the massacre of civilians at Drogheda and Wexford.

Cromwell's foreign policy was driven by his belief in English exceptionalism and his desire to extend English influence and power around the world. He saw England as a chosen nation with a special role to play in world affairs, and his aggressive foreign policy reflected this belief. However, his wars were costly and left England heavily in debt, and they also generated significant opposition both at home and abroad.

However, Cromwell's rule was also marked by authoritarianism and repression. He dissolved the Rump Parliament in 1653 and ruled by decree, using a network of spies and informants to monitor his subjects. The Commonwealth also saw brutal suppression of uprisings in Scotland and Ireland, which were seen as threats to the new regime.

The Commonwealth came to an end in 1660, when the monarchy was restored with the ascension of King Charles II. Many of the changes made during the Commonwealth, such as the abolition of the monarchy and the establishment of a professional army, were retained, but the authoritarianism and repression of the Cromwellian regime were rejected.